Electropolishing (also known as electrochemical polishing or electrolytic polishing) is critical to reducing contaminants in equipment used in industries that touch peoples’ health. These industries include food and beverages, cosmetics and -- perhaps most critical -- pharmaceuticals and biotechnology. During the normal course of alloy fabrication, bending, grinding, machining and other normal processes change the metal surfaces significantly. These alterations take the form of burrs, scales and tooling marks. Without treatment these surface imperfections can be a focal point for infection or metal contamination.
Electropolishing removes this surface material from metal. It deburrs and polishes metal parts. This is particularly useful when applied to objects of complex shape, such as the storage and pressurized tanks used in the pharmaceutical and biotechnology industries. Electropolishing may also be used in place of the abrasive fine polishing in microstructural preparation. Through electropolishing, an alloy fabrication professional can achieve as much as a 50 percent improvement in the average roughness height.
Smoother, cleaner surfaces
Electropolishing occurs through the electrolytic removal of metal in a highly ionic solution by means of an electric potential and current. In this process, the work piece is typically immersed in a temperature-controlled bath of electrolyte. It is then connected to the positive terminal of a DC power supply, while the negative terminal is attached to the cathode. A current passes from the anode, where metal on the surface is oxidized and dissolved in the electrolyte, to the cathode. At the cathode, a reduction reaction occurs.
During microfinishing, surface metal on the work piece is greatly reduced, leaving the part much smoother both visually and measurably by a profilometer. Generally speaking, Ra surfaces are improved by 50 percent (e.g., a 14 Ra finish becomes a 7 Ra finish).
A Beneficial Process
Highly sophisticated surface analysis reveals the many benefits that are derived from the fine surface finishing achieved through electropolishing. In general, it is much better to restore a metal surface than to coat a defect. Electropolishing has proven itself to be a critical step in alloy fabrication, a step that is best performed by superior crafts people employed by superior vendors and service providers.
American Alloy Fabricators, Inc. partners with leading pharmaceutical and biotech companies to design and fabricate process equipment used in their research and production facilities. For more information on our wide range of products and services, contact American Alloy Fabricator, Inc., at 610-635-0205 or via the Web at http://www.americanalloyfab.com/contact.html.
